Field of the Invention
The invention relates to an electronic device and a power supplying method thereof and, more particularly, to a charging method of an electronic device.
Description of the Related Art
As electronic technology develops, electronic products are necessary in daily life. Conventionally, the electronic products usually charged by a signal transmission interface for portability requirement, such as a universal serial bus (USB) interface.
Please refer to FIG. 1, FIG. 1 is a schematic diagram showing that a conventional electronic device is charged. A portable electronic device 110 is connected to a connection interface CN2 of a USB charger 120 via a connection interface CN1, and it receives power transmitted by a pin VBUS2 of the USB charger 120. Via a connection between the connection interfaces CN1 and CN2, a pin VBUS1 is electrically connected to the pin VBUS2, a pin D1− is electrically connected to a pin D2−, and a pin D1+ is electrically connected to a pin D2, and both the connection interfaces CN1 and CN2 are connected to a reference ground terminal GND. In FIG. 1, the portable electronic device 110 can determine a maximum electric power provided from the USB charger 120 by detecting a voltage between the pins D1− and D1. The relationship between the resistance across the pins D2− and D2+ of the USB charger 120 and the maximum provided electric power are predefined (for example, when the pins D2− and D2+ are short-circuited, the maximum electric power of 1.5 A can be provided).
As stated above, the portable electronic device 110 can determine whether to be charged by detecting the maximum electric power provided by the USB charger 120. However, when the portable electronic device 110 has a new charging specification, additional hardware is needed (for example, an integrated circuit for identifying is additionally disposed at the end of the portable electronic device 110 and the end of USB charger 120, respectively), which increases the cost.